1 /* Copyright (c) 2008-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
14 #define DW_LANG_Objc DW_LANG_ObjC /* fix spelling error in older dwarf.h */
16 #include <elfutils/libdw.h>
18 #include <simgrid_config.h>
19 #include <simgrid/util.hpp>
21 #include <xbt/sysdep.h>
23 #include <simgrid/util.hpp>
25 #include "mc_object_info.h"
26 #include "mc_private.h"
28 #include "mc/Process.hpp"
29 #include "mc/ObjectInformation.hpp"
30 #include "mc/Variable.hpp"
32 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing");
34 /** \brief The default DW_TAG_lower_bound for a given DW_AT_language.
36 * The default for a given language is defined in the DWARF spec.
38 * \param language consant as defined by the DWARf spec
40 static uint64_t MC_dwarf_default_lower_bound(int lang);
42 /** \brief Computes the the element_count of a DW_TAG_enumeration_type DIE
44 * This is the number of elements in a given array dimension.
46 * A reference of the compilation unit (DW_TAG_compile_unit) is
47 * needed because the default lower bound (when there is no DW_AT_lower_bound)
48 * depends of the language of the compilation unit (DW_AT_language).
50 * \param die DIE for the DW_TAG_enumeration_type or DW_TAG_subrange_type
51 * \param unit DIE of the DW_TAG_compile_unit
53 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die * die,
56 /** \brief Computes the number of elements of a given DW_TAG_array_type.
58 * \param die DIE for the DW_TAG_array_type
60 static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit);
62 /** \brief Process a DIE
64 * \param info the resulting object fot the library/binary file (output)
65 * \param die the current DIE
66 * \param unit the DIE of the compile unit of the current DIE
67 * \param frame containg frame if any
69 static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
70 Dwarf_Die * unit, simgrid::mc::Frame* frame,
73 /** \brief Process a type DIE
75 static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
76 Dwarf_Die * unit, simgrid::mc::Frame* frame,
79 /** \brief Calls MC_dwarf_handle_die on all childrend of the given die
81 * \param info the resulting object fot the library/binary file (output)
82 * \param die the current DIE
83 * \param unit the DIE of the compile unit of the current DIE
84 * \param frame containg frame if any
86 static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
87 Dwarf_Die * unit, simgrid::mc::Frame* frame,
90 /** \brief Handle a variable (DW_TAG_variable or other)
92 * \param info the resulting object fot the library/binary file (output)
93 * \param die the current DIE
94 * \param unit the DIE of the compile unit of the current DIE
95 * \param frame containg frame if any
97 static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
98 Dwarf_Die * unit, simgrid::mc::Frame* frame,
101 /** \brief Get the DW_TAG_type of the DIE
104 * \return DW_TAG_type attribute as a new string (NULL if none)
106 static std::uint64_t MC_dwarf_at_type(Dwarf_Die * die);
111 enum class TagClass {
120 /*** Class of forms defined in the DWARF standard */
121 enum class FormClass {
123 Address, // Location in the program's address space
124 Block, // Arbitrary block of bytes
127 Flag, // Boolean value
128 Reference, // Reference to another DIE
129 ExprLoc, // DWARF expression/location description
138 TagClass classify_tag(int tag)
142 case DW_TAG_array_type:
143 case DW_TAG_class_type:
144 case DW_TAG_enumeration_type:
146 case DW_TAG_pointer_type:
147 case DW_TAG_reference_type:
148 case DW_TAG_rvalue_reference_type:
149 case DW_TAG_string_type:
150 case DW_TAG_structure_type:
151 case DW_TAG_subroutine_type:
152 case DW_TAG_union_type:
153 case DW_TAG_ptr_to_member_type:
154 case DW_TAG_set_type:
155 case DW_TAG_subrange_type:
156 case DW_TAG_base_type:
157 case DW_TAG_const_type:
158 case DW_TAG_file_type:
159 case DW_TAG_packed_type:
160 case DW_TAG_volatile_type:
161 case DW_TAG_restrict_type:
162 case DW_TAG_interface_type:
163 case DW_TAG_unspecified_type:
164 case DW_TAG_shared_type:
165 return TagClass::Type;
167 case DW_TAG_subprogram:
168 return TagClass::Subprogram;
170 case DW_TAG_variable:
171 case DW_TAG_formal_parameter:
172 return TagClass::Variable;
174 case DW_TAG_lexical_block:
175 case DW_TAG_try_block:
176 case DW_TAG_catch_block:
177 case DW_TAG_inlined_subroutine:
178 case DW_TAG_with_stmt:
179 return TagClass::Scope;
181 case DW_TAG_namespace:
182 return TagClass::Namespace;
185 return TagClass::Unknown;
189 /** \brief Find the DWARF data class for a given DWARF data form
191 * This mapping is defined in the DWARF spec.
193 * \param form The form (values taken from the DWARF spec)
194 * \return An internal representation for the corresponding class
196 FormClass classify_form(int form)
200 return FormClass::Address;
205 return FormClass::Block;
212 return FormClass::Constant;
215 return FormClass::String;
216 case DW_FORM_ref_addr:
221 case DW_FORM_ref_udata:
222 return FormClass::Reference;
224 case DW_FORM_flag_present:
225 return FormClass::Flag;
226 case DW_FORM_exprloc:
227 return FormClass::ExprLoc;
231 return FormClass::Unknown;
239 /** \brief Get the name of the tag of a given DIE
242 * \return name of the tag of this DIE
244 static inline const char *MC_dwarf_die_tagname(Dwarf_Die * die)
246 return MC_dwarf_tagname(dwarf_tag(die));
251 /** \brief Get an attribute of a given DIE as a string
254 * \param attribute attribute
255 * \return value of the given attribute of the given DIE
257 static const char *MC_dwarf_attr_integrate_string(Dwarf_Die * die,
260 Dwarf_Attribute attr;
261 if (!dwarf_attr_integrate(die, attribute, &attr)) {
264 return dwarf_formstring(&attr);
268 /** \brief Get the linkage name of a DIE.
270 * Use either DW_AT_linkage_name or DW_AT_MIPS_linkage_name.
271 * DW_AT_linkage_name is standardized since DWARF 4.
272 * Before this version of DWARF, the MIPS extensions
273 * DW_AT_MIPS_linkage_name is used (at least by GCC).
276 * \return linkage name of the given DIE (or NULL)
278 static const char *MC_dwarf_at_linkage_name(Dwarf_Die * die)
280 const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_linkage_name);
282 name = MC_dwarf_attr_integrate_string(die, DW_AT_MIPS_linkage_name);
286 static Dwarf_Off MC_dwarf_attr_dieoffset(Dwarf_Die * die, int attribute)
288 Dwarf_Attribute attr;
289 if (dwarf_hasattr_integrate(die, attribute) == 0)
291 dwarf_attr_integrate(die, attribute, &attr);
292 Dwarf_Die subtype_die;
293 if (dwarf_formref_die(&attr, &subtype_die) == NULL)
294 xbt_die("Could not find DIE");
295 return dwarf_dieoffset(&subtype_die);
298 static Dwarf_Off MC_dwarf_attr_integrate_dieoffset(Dwarf_Die * die,
301 Dwarf_Attribute attr;
302 if (dwarf_hasattr_integrate(die, attribute) == 0)
304 dwarf_attr_integrate(die, DW_AT_type, &attr);
305 Dwarf_Die subtype_die;
306 if (dwarf_formref_die(&attr, &subtype_die) == NULL)
307 xbt_die("Could not find DIE");
308 return dwarf_dieoffset(&subtype_die);
311 /** \brief Find the type/subtype (DW_AT_type) for a DIE
314 * \return DW_AT_type reference as a global offset in hexadecimal (or NULL)
317 std::uint64_t MC_dwarf_at_type(Dwarf_Die * die)
319 return MC_dwarf_attr_integrate_dieoffset(die, DW_AT_type);
322 static uint64_t MC_dwarf_attr_integrate_addr(Dwarf_Die * die, int attribute)
324 Dwarf_Attribute attr;
325 if (dwarf_attr_integrate(die, attribute, &attr) == NULL)
328 if (dwarf_formaddr(&attr, &value) == 0)
329 return (uint64_t) value;
334 static uint64_t MC_dwarf_attr_integrate_uint(Dwarf_Die * die, int attribute,
335 uint64_t default_value)
337 Dwarf_Attribute attr;
338 if (dwarf_attr_integrate(die, attribute, &attr) == NULL)
339 return default_value;
341 return dwarf_formudata(dwarf_attr_integrate(die, attribute, &attr),
342 &value) == 0 ? (uint64_t) value : default_value;
345 static bool MC_dwarf_attr_flag(Dwarf_Die * die, int attribute, bool integrate)
347 Dwarf_Attribute attr;
348 if ((integrate ? dwarf_attr_integrate(die, attribute, &attr)
349 : dwarf_attr(die, attribute, &attr)) == 0)
353 if (dwarf_formflag(&attr, &result))
354 xbt_die("Unexpected form for attribute %s", MC_dwarf_attrname(attribute));
358 /** \brief Find the default lower bound for a given language
360 * The default lower bound of an array (when DW_TAG_lower_bound
361 * is missing) depends on the language of the compilation unit.
363 * \param lang Language of the compilation unit (values defined in the DWARF spec)
364 * \return Default lower bound of an array in this compilation unit
366 static uint64_t MC_dwarf_default_lower_bound(int lang)
372 case DW_LANG_C_plus_plus:
376 case DW_LANG_ObjC_plus_plus:
382 case DW_LANG_Fortran77:
383 case DW_LANG_Fortran90:
384 case DW_LANG_Fortran95:
385 case DW_LANG_Modula2:
386 case DW_LANG_Pascal83:
388 case DW_LANG_Cobol74:
389 case DW_LANG_Cobol85:
392 xbt_die("No default DW_TAG_lower_bound for language %i and none given",
398 /** \brief Finds the number of elements in a DW_TAG_subrange_type or DW_TAG_enumeration_type DIE
401 * \param unit DIE of the compilation unit
402 * \return number of elements in the range
404 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die * die,
407 xbt_assert(dwarf_tag(die) == DW_TAG_enumeration_type
408 || dwarf_tag(die) == DW_TAG_subrange_type,
409 "MC_dwarf_subrange_element_count called with DIE of type %s",
410 MC_dwarf_die_tagname(die));
412 // Use DW_TAG_count if present:
413 if (dwarf_hasattr_integrate(die, DW_AT_count))
414 return MC_dwarf_attr_integrate_uint(die, DW_AT_count, 0);
415 // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:
417 if (!dwarf_hasattr_integrate(die, DW_AT_upper_bound))
418 // This is not really 0, but the code expects this (we do not know):
421 uint64_t upper_bound =
422 MC_dwarf_attr_integrate_uint(die, DW_AT_upper_bound, -1);
424 uint64_t lower_bound = 0;
425 if (dwarf_hasattr_integrate(die, DW_AT_lower_bound))
426 lower_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_lower_bound, -1);
428 lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
429 return upper_bound - lower_bound + 1;
432 /** \brief Finds the number of elements in a array type (DW_TAG_array_type)
434 * The compilation unit might be needed because the default lower
435 * bound depends on the language of the compilation unit.
437 * \param die the DIE of the DW_TAG_array_type
438 * \param unit the DIE of the compilation unit
439 * \return number of elements in this array type
441 static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit)
443 xbt_assert(dwarf_tag(die) == DW_TAG_array_type,
444 "MC_dwarf_array_element_count called with DIE of type %s",
445 MC_dwarf_die_tagname(die));
450 for (res = dwarf_child(die, &child); res == 0;
451 res = dwarf_siblingof(&child, &child)) {
452 int child_tag = dwarf_tag(&child);
453 if (child_tag == DW_TAG_subrange_type
454 || child_tag == DW_TAG_enumeration_type)
455 result *= MC_dwarf_subrange_element_count(&child, unit);
462 /** Sort the variable by name and address.
464 * We could use boost::container::flat_set instead.
466 static bool MC_compare_variable(
467 simgrid::mc::Variable const& a, simgrid::mc::Variable const& b)
469 int cmp = strcmp(a.name.c_str(), b.name.c_str());
475 return a.address < b.address;
478 // ***** simgrid::mc::Type*
480 /** \brief Initialize the location of a member of a type
481 * (DW_AT_data_member_location of a DW_TAG_member).
483 * \param type a type (struct, class)
484 * \param member the member of the type
485 * \param child DIE of the member (DW_TAG_member)
487 static void MC_dwarf_fill_member_location(
488 simgrid::mc::Type* type, simgrid::mc::Member* member, Dwarf_Die * child)
490 if (dwarf_hasattr(child, DW_AT_data_bit_offset))
491 xbt_die("Can't groke DW_AT_data_bit_offset.");
493 if (!dwarf_hasattr_integrate(child, DW_AT_data_member_location)) {
494 if (type->type == DW_TAG_union_type)
497 ("Missing DW_AT_data_member_location field in DW_TAG_member %s of type <%"
498 PRIx64 ">%s", member->name.c_str(),
499 (uint64_t) type->id, type->name.c_str());
502 Dwarf_Attribute attr;
503 dwarf_attr_integrate(child, DW_AT_data_member_location, &attr);
504 int form = dwarf_whatform(&attr);
505 simgrid::dwarf::FormClass form_class = simgrid::dwarf::classify_form(form);
506 switch (form_class) {
507 case simgrid::dwarf::FormClass::ExprLoc:
508 case simgrid::dwarf::FormClass::Block:
509 // Location expression:
513 if (dwarf_getlocation(&attr, &expr, &len))
515 ("Could not read location expression DW_AT_data_member_location in DW_TAG_member %s of type <%"
516 PRIx64 ">%s", MC_dwarf_attr_integrate_string(child, DW_AT_name),
517 (uint64_t) type->id, type->name.c_str());
518 member->location_expression = simgrid::mc::DwarfExpression(expr, expr+len);
521 case simgrid::dwarf::FormClass::Constant:
522 // Offset from the base address of the object:
525 if (!dwarf_formudata(&attr, &offset))
526 member->offset(offset);
528 xbt_die("Cannot get %s location <%" PRIx64 ">%s",
529 MC_dwarf_attr_integrate_string(child, DW_AT_name),
530 (uint64_t) type->id, type->name.c_str());
533 case simgrid::dwarf::FormClass::LocListPtr:
534 // Reference to a location list:
536 case simgrid::dwarf::FormClass::Reference:
537 // It's supposed to be possible in DWARF2 but I couldn't find its semantic
540 xbt_die("Can't handle form class (%i) / form 0x%x as DW_AT_member_location",
541 (int) form_class, form);
546 /** \brief Populate the list of members of a type
548 * \param info ELF object containing the type DIE
549 * \param die DIE of the type
550 * \param unit DIE of the compilation unit containing the type DIE
551 * \param type the type
553 static void MC_dwarf_add_members(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
554 Dwarf_Die * unit, simgrid::mc::Type* type)
558 xbt_assert(type->members.empty());
559 for (res = dwarf_child(die, &child); res == 0;
560 res = dwarf_siblingof(&child, &child)) {
561 int tag = dwarf_tag(&child);
562 if (tag == DW_TAG_member || tag == DW_TAG_inheritance) {
564 // Skip declarations:
565 if (MC_dwarf_attr_flag(&child, DW_AT_declaration, false))
568 // Skip compile time constants:
569 if (dwarf_hasattr(&child, DW_AT_const_value))
572 // TODO, we should use another type (because is is not a type but a member)
573 simgrid::mc::Member member;
574 member.inheritance = tag == DW_TAG_inheritance;
576 const char *name = MC_dwarf_attr_integrate_string(&child, DW_AT_name);
580 MC_dwarf_attr_integrate_uint(&child, DW_AT_byte_size, 0);
581 member.type_id = MC_dwarf_at_type(&child);
583 if (dwarf_hasattr(&child, DW_AT_data_bit_offset))
584 xbt_die("Can't groke DW_AT_data_bit_offset.");
586 MC_dwarf_fill_member_location(type, &member, &child);
589 xbt_die("Missing type for member %s of <%" PRIx64 ">%s",
591 (uint64_t) type->id, type->name.c_str());
593 type->members.push_back(std::move(member));
598 /** \brief Create a MC type object from a DIE
600 * \param info current object info object
601 * \param DIE (for a given type);
602 * \param unit compilation unit of the current DIE
603 * \return MC representation of the type
605 static simgrid::mc::Type MC_dwarf_die_to_type(
606 simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
607 Dwarf_Die * unit, simgrid::mc::Frame* frame,
610 simgrid::mc::Type type;
611 type.type = dwarf_tag(die);
612 type.name = std::string();
613 type.element_count = -1;
616 type.id = dwarf_dieoffset(die);
618 const char *prefix = "";
620 case DW_TAG_structure_type:
623 case DW_TAG_union_type:
626 case DW_TAG_class_type:
633 const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
635 char* full_name = ns ? bprintf("%s%s::%s", prefix, ns, name) :
636 bprintf("%s%s", prefix, name);
637 type.name = std::string(full_name);
641 type.type_id = MC_dwarf_at_type(die);
643 // Some compilers do not emit DW_AT_byte_size for pointer_type,
644 // so we fill this. We currently assume that the model-checked process is in
645 // the same architecture..
646 if (type.type == DW_TAG_pointer_type)
647 type.byte_size = sizeof(void*);
649 // Computation of the byte_size;
650 if (dwarf_hasattr_integrate(die, DW_AT_byte_size))
651 type.byte_size = MC_dwarf_attr_integrate_uint(die, DW_AT_byte_size, 0);
652 else if (type.type == DW_TAG_array_type
653 || type.type == DW_TAG_structure_type
654 || type.type == DW_TAG_class_type) {
656 if (dwarf_aggregate_size(die, &size) == 0)
657 type.byte_size = size;
661 case DW_TAG_array_type:
662 type.element_count = MC_dwarf_array_element_count(die, unit);
663 // TODO, handle DW_byte_stride and (not) DW_bit_stride
666 case DW_TAG_pointer_type:
667 case DW_TAG_reference_type:
668 case DW_TAG_rvalue_reference_type:
669 type.is_pointer_type = 1;
672 case DW_TAG_structure_type:
673 case DW_TAG_union_type:
674 case DW_TAG_class_type:
675 MC_dwarf_add_members(info, die, unit, &type);
676 char *new_ns = ns == NULL ? xbt_strdup(type.name.c_str())
677 : bprintf("%s::%s", ns, name);
678 MC_dwarf_handle_children(info, die, unit, frame, new_ns);
683 return std::move(type);
686 static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
687 Dwarf_Die * unit, simgrid::mc::Frame* frame,
690 simgrid::mc::Type type = MC_dwarf_die_to_type(info, die, unit, frame, ns);
691 auto& t = (info->types[type.id] = std::move(type));
692 if (!t.name.empty() && type.byte_size != 0)
693 info->full_types_by_name[t.name] = &t;
696 static int mc_anonymous_variable_index = 0;
698 static std::unique_ptr<simgrid::mc::Variable> MC_die_to_variable(
699 simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
700 Dwarf_Die * unit, simgrid::mc::Frame* frame,
703 // Skip declarations:
704 if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
707 // Skip compile time constants:
708 if (dwarf_hasattr(die, DW_AT_const_value))
711 Dwarf_Attribute attr_location;
712 if (dwarf_attr(die, DW_AT_location, &attr_location) == NULL)
713 // No location: do not add it ?
716 std::unique_ptr<simgrid::mc::Variable> variable =
717 std::unique_ptr<simgrid::mc::Variable>(new simgrid::mc::Variable());
718 variable->dwarf_offset = dwarf_dieoffset(die);
719 variable->global = frame == NULL; // Can be override base on DW_AT_location
720 variable->object_info = info;
722 const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
724 variable->name = name;
725 variable->type_id = MC_dwarf_at_type(die);
727 int form = dwarf_whatform(&attr_location);
728 simgrid::dwarf::FormClass form_class;
729 if (form == DW_FORM_sec_offset)
730 form_class = simgrid::dwarf::FormClass::Constant;
732 form_class = simgrid::dwarf::classify_form(form);
733 switch (form_class) {
734 case simgrid::dwarf::FormClass::ExprLoc:
735 case simgrid::dwarf::FormClass::Block:
736 // Location expression:
740 if (dwarf_getlocation(&attr_location, &expr, &len)) {
742 "Could not read location expression in DW_AT_location "
743 "of variable <%" PRIx64 ">%s",
744 (uint64_t) variable->dwarf_offset,
745 variable->name.c_str());
748 if (len == 1 && expr[0].atom == DW_OP_addr) {
749 variable->global = 1;
750 uintptr_t offset = (uintptr_t) expr[0].number;
751 uintptr_t base = (uintptr_t) info->base_address();
752 variable->address = (void *) (base + offset);
754 simgrid::mc::LocationListEntry entry;
755 entry.expression = {expr, expr + len};
756 variable->location_list = { std::move(entry) };
762 case simgrid::dwarf::FormClass::LocListPtr:
763 case simgrid::dwarf::FormClass::Constant:
764 // Reference to location list:
765 mc_dwarf_location_list_init(
766 &variable->location_list, info, die,
771 xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location "
772 "in <%" PRIx64 ">%s",
773 form, form, (int) form_class, (int) form_class,
774 (uint64_t) variable->dwarf_offset,
775 variable->name.c_str());
778 // Handle start_scope:
779 if (dwarf_hasattr(die, DW_AT_start_scope)) {
780 Dwarf_Attribute attr;
781 dwarf_attr(die, DW_AT_start_scope, &attr);
782 int form = dwarf_whatform(&attr);
783 simgrid::dwarf::FormClass form_class = simgrid::dwarf::classify_form(form);
784 switch (form_class) {
785 case simgrid::dwarf::FormClass::Constant:
788 variable->start_scope =
789 dwarf_formudata(&attr, &value) == 0 ? (size_t) value : 0;
793 case simgrid::dwarf::FormClass::RangeListPtr: // TODO
796 ("Unhandled form 0x%x, class 0x%X for DW_AT_start_scope of variable %s",
797 form, (int) form_class, name == NULL ? "?" : name);
801 if (ns && variable->global)
803 std::string(ns) + "::" + variable->name;
805 // The current code needs a variable name,
806 // generate a fake one:
807 if (variable->name.empty())
809 "@anonymous#" + std::to_string(mc_anonymous_variable_index++);
811 return std::move(variable);
814 static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
815 Dwarf_Die * unit, simgrid::mc::Frame* frame,
818 std::unique_ptr<simgrid::mc::Variable> variable =
819 MC_die_to_variable(info, die, unit, frame, ns);
822 // Those arrays are sorted later:
823 else if (variable->global)
824 info->global_variables.push_back(std::move(*variable));
825 else if (frame != nullptr)
826 frame->variables.push_back(std::move(*variable));
828 xbt_die("No frame for this local variable");
831 static void MC_dwarf_handle_scope_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
832 Dwarf_Die * unit, simgrid::mc::Frame* parent_frame,
835 // TODO, handle DW_TAG_type/DW_TAG_location for DW_TAG_with_stmt
836 int tag = dwarf_tag(die);
837 simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag);
839 // (Template) Subprogram declaration:
840 if (klass == simgrid::dwarf::TagClass::Subprogram
841 && MC_dwarf_attr_flag(die, DW_AT_declaration, false))
844 if (klass == simgrid::dwarf::TagClass::Scope)
845 xbt_assert(parent_frame, "No parent scope for this scope");
847 simgrid::mc::Frame frame;
850 frame.id = dwarf_dieoffset(die);
851 frame.object_info = info;
853 if (klass == simgrid::dwarf::TagClass::Subprogram) {
854 const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
856 frame.name = std::string(ns) + "::" + name;
863 frame.abstract_origin_id =
864 MC_dwarf_attr_dieoffset(die, DW_AT_abstract_origin);
866 // This is the base address for DWARF addresses.
867 // Relocated addresses are offset from this base address.
868 // See DWARF4 spec 7.5
869 void *base = info->base_address();
871 // TODO, support DW_AT_ranges
872 uint64_t low_pc = MC_dwarf_attr_integrate_addr(die, DW_AT_low_pc);
873 frame.low_pc = low_pc ? ((char *) base) + low_pc : 0;
876 Dwarf_Attribute attr;
877 if (!dwarf_attr_integrate(die, DW_AT_high_pc, &attr)) {
878 xbt_die("Missing DW_AT_high_pc matching with DW_AT_low_pc");
884 switch (simgrid::dwarf::classify_form(dwarf_whatform(&attr))) {
886 // DW_AT_high_pc if an offset from the low_pc:
887 case simgrid::dwarf::FormClass::Constant:
889 if (dwarf_formsdata(&attr, &offset) != 0)
890 xbt_die("Could not read constant");
891 frame.high_pc = (void *) ((char *) frame.low_pc + offset);
894 // DW_AT_high_pc is a relocatable address:
895 case simgrid::dwarf::FormClass::Address:
896 if (dwarf_formaddr(&attr, &high_pc) != 0)
897 xbt_die("Could not read address");
898 frame.high_pc = ((char *) base) + high_pc;
902 xbt_die("Unexpected class for DW_AT_high_pc");
907 if (klass == simgrid::dwarf::TagClass::Subprogram) {
908 Dwarf_Attribute attr_frame_base;
909 if (dwarf_attr_integrate(die, DW_AT_frame_base, &attr_frame_base))
910 mc_dwarf_location_list_init(&frame.frame_base, info, die,
915 MC_dwarf_handle_children(info, die, unit, &frame, ns);
917 // Someone needs this to be sorted but who?
918 std::sort(frame.variables.begin(), frame.variables.end(),
919 MC_compare_variable);
922 if (klass == simgrid::dwarf::TagClass::Subprogram)
923 info->subprograms[frame.id] = frame;
924 else if (klass == simgrid::dwarf::TagClass::Scope)
925 parent_frame->scopes.push_back(std::move(frame));
928 static void mc_dwarf_handle_namespace_die(simgrid::mc::ObjectInformation* info,
929 Dwarf_Die * die, Dwarf_Die * unit,
930 simgrid::mc::Frame* frame,
933 const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
935 xbt_die("Unexpected namespace in a subprogram");
936 char *new_ns = ns == NULL ? xbt_strdup(name)
937 : bprintf("%s::%s", ns, name);
938 MC_dwarf_handle_children(info, die, unit, frame, new_ns);
942 static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
943 Dwarf_Die * unit, simgrid::mc::Frame* frame,
946 // For each child DIE:
949 for (res = dwarf_child(die, &child); res == 0;
950 res = dwarf_siblingof(&child, &child)) {
951 MC_dwarf_handle_die(info, &child, unit, frame, ns);
955 static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
956 Dwarf_Die * unit, simgrid::mc::Frame* frame,
959 int tag = dwarf_tag(die);
960 simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag);
964 case simgrid::dwarf::TagClass::Type:
965 MC_dwarf_handle_type_die(info, die, unit, frame, ns);
968 // Subprogram or scope:
969 case simgrid::dwarf::TagClass::Subprogram:
970 case simgrid::dwarf::TagClass::Scope:
971 MC_dwarf_handle_scope_die(info, die, unit, frame, ns);
975 case simgrid::dwarf::TagClass::Variable:
976 MC_dwarf_handle_variable_die(info, die, unit, frame, ns);
979 case simgrid::dwarf::TagClass::Namespace:
980 mc_dwarf_handle_namespace_die(info, die, unit, frame, ns);
989 /** \brief Populate the debugging informations of the given ELF object
991 * Read the DWARf information of the EFFL object and populate the
992 * lists of types, variables, functions.
994 void MC_dwarf_get_variables(simgrid::mc::ObjectInformation* info)
996 int fd = open(info->file_name.c_str(), O_RDONLY);
998 xbt_die("Could not open file %s", info->file_name.c_str());
999 Dwarf *dwarf = dwarf_begin(fd, DWARF_C_READ);
1001 xbt_die("Missing debugging information in %s\n"
1002 "Your program and its dependencies must have debugging information.\n"
1003 "You might want to recompile with -g or install the suitable debugging package.\n",
1004 info->file_name.c_str());
1005 // For each compilation unit:
1006 Dwarf_Off offset = 0;
1007 Dwarf_Off next_offset = 0;
1010 while (dwarf_nextcu(dwarf, offset, &next_offset, &length, NULL, NULL, NULL) ==
1013 if (dwarf_offdie(dwarf, offset + length, &unit_die) != NULL)
1014 MC_dwarf_handle_children(info, &unit_die, &unit_die, NULL, NULL);
1015 offset = next_offset;
1022 // ***** Functions index
1024 static int MC_compare_frame_index_items(simgrid::mc::FunctionIndexEntry* a,
1025 simgrid::mc::FunctionIndexEntry* b)
1027 if (a->low_pc < b->low_pc)
1029 else if (a->low_pc == b->low_pc)
1035 static void MC_make_functions_index(simgrid::mc::ObjectInformation* info)
1037 info->functions_index.clear();
1039 for (auto& e : info->subprograms) {
1040 if (e.second.low_pc == nullptr)
1042 simgrid::mc::FunctionIndexEntry entry;
1043 entry.low_pc = e.second.low_pc;
1044 entry.function = &e.second;
1045 info->functions_index.push_back(entry);
1048 info->functions_index.shrink_to_fit();
1050 // Sort the array by low_pc:
1051 std::sort(info->functions_index.begin(), info->functions_index.end(),
1052 [](simgrid::mc::FunctionIndexEntry const& a,
1053 simgrid::mc::FunctionIndexEntry const& b)
1055 return a.low_pc < b.low_pc;
1059 static void MC_post_process_variables(simgrid::mc::ObjectInformation* info)
1061 // Someone needs this to be sorted but who?
1062 std::sort(info->global_variables.begin(), info->global_variables.end(),
1063 MC_compare_variable);
1065 for(simgrid::mc::Variable& variable : info->global_variables)
1066 if (variable.type_id)
1067 variable.type = simgrid::util::find_map_ptr(
1068 info->types, variable.type_id);
1071 static void mc_post_process_scope(simgrid::mc::ObjectInformation* info, simgrid::mc::Frame* scope)
1074 if (scope->tag == DW_TAG_inlined_subroutine) {
1075 // Attach correct namespaced name in inlined subroutine:
1076 auto i = info->subprograms.find(scope->abstract_origin_id);
1077 xbt_assert(i != info->subprograms.end(),
1078 "Could not lookup abstract origin %" PRIx64,
1079 (std::uint64_t) scope->abstract_origin_id);
1080 scope->name = i->second.name;
1084 for (simgrid::mc::Variable& variable : scope->variables)
1085 if (variable.type_id)
1086 variable.type = simgrid::util::find_map_ptr(
1087 info->types, variable.type_id);
1089 // Recursive post-processing of nested-scopes:
1090 for (simgrid::mc::Frame& nested_scope : scope->scopes)
1091 mc_post_process_scope(info, &nested_scope);
1096 simgrid::mc::Type* MC_resolve_type(
1097 simgrid::mc::ObjectInformation* info, unsigned type_id)
1101 simgrid::mc::Type* type = simgrid::util::find_map_ptr(info->types, type_id);
1102 if (type == nullptr)
1105 // We already have the information on the type:
1106 if (type->byte_size != 0)
1109 // Don't have a name, we can't find a more complete version:
1110 if (type->name.empty())
1113 // Try to find a more complete description of the type:
1114 // We need to fix in order to support C++.
1115 simgrid::mc::Type** subtype = simgrid::util::find_map_ptr(
1116 info->full_types_by_name, type->name);
1122 static void MC_post_process_types(simgrid::mc::ObjectInformation* info)
1124 // Lookup "subtype" field:
1125 for(auto& i : info->types) {
1126 i.second.subtype = MC_resolve_type(info, i.second.type_id);
1127 for (simgrid::mc::Member& member : i.second.members)
1128 member.type = MC_resolve_type(info, member.type_id);
1132 /** \brief Finds informations about a given shared object/executable */
1133 std::shared_ptr<simgrid::mc::ObjectInformation> MC_find_object_info(
1134 std::vector<simgrid::mc::VmMap> const& maps, const char *name, int executable)
1136 std::shared_ptr<simgrid::mc::ObjectInformation> result =
1137 std::make_shared<simgrid::mc::ObjectInformation>();
1139 result->flags |= simgrid::mc::ObjectInformation::Executable;
1140 result->file_name = name;
1141 MC_find_object_address(maps, result.get());
1142 MC_dwarf_get_variables(result.get());
1143 MC_post_process_variables(result.get());
1144 MC_post_process_types(result.get());
1145 for (auto& entry : result.get()->subprograms)
1146 mc_post_process_scope(result.get(), &entry.second);
1147 MC_make_functions_index(result.get());
1148 return std::move(result);
1151 /*************************************************************************/
1153 void MC_post_process_object_info(simgrid::mc::Process* process, simgrid::mc::ObjectInformation* info)
1155 for (auto& i : info->types) {
1157 simgrid::mc::Type* type = &(i.second);
1158 simgrid::mc::Type* subtype = type;
1159 while (subtype->type == DW_TAG_typedef
1160 || subtype->type == DW_TAG_volatile_type
1161 || subtype->type == DW_TAG_const_type)
1162 if (subtype->subtype)
1163 subtype = subtype->subtype;
1167 // Resolve full_type:
1168 if (!subtype->name.empty() && subtype->byte_size == 0) {
1169 for (auto const& object_info : process->object_infos) {
1170 auto i = object_info->full_types_by_name.find(subtype->name);
1171 if (i != object_info->full_types_by_name.end()
1172 && !i->second->name.empty() && i->second->byte_size) {
1173 type->full_type = i->second;
1177 } else type->full_type = subtype;